Minimal airline delays, cancellations a day after US outage

Delays and cancellations among flights across the United States were minimal on Thursday, a day after a system that offers safety information to pilots failed, grounding U.S. air traffic and leading to thousands of stranded travelers.

There were 636 delays into, within or out of the U.S. as of Thursday morning, according to flight-tracking website FlightAware. There were 82 cancellations.

The Federal Aviation Administration said Wednesday that preliminary indications “traced the outage to a damaged database file.” The agency said it would take steps to avoid another similar disruption.

The breakdown showed how much American air travel depends on the computer system that generates alerts called NOTAMs — or Notice to Air Missions.

Before a plane takes off, pilots and airline dispatchers must review the notices, which include details about bad weather, runway closures or other temporary factors that could affect the flight. The system was once telephone-based but moved online years ago.

The system broke down late Tuesday and was not fixed until midmorning Wednesday. The FAA took the rare step of preventing any planes from taking off for a time, and the cascading chaos led to more than 1,300 flight cancellations and 9,000 delays by early Wednesday evening on the East Coast, according to FlightAware.

Transportation Secretary Pete Buttigieg told a news conference that the problems “led to a ground stop because of the way safety information was moving through the system.”

After the failures were fixed, he warned that travelers could continue to see some effects “rippling through the system.”

Buttigieg said his agency would now try to learn why the system went down.

Longtime aviation insiders could not recall an outage of such magnitude caused by a technology failure. Some...